The present invention relates to a system for purifying room air. More particularly, it relates to a modular air-purifying system including separate, independently positionable blower, filter and supply modules.
In recent years, there has been a growing interest to improve environmental air conditions in homes and in commercial settings, such as offices, restaurants, taverns, bowling alleys, hospitals, laboratories, lavatories, and the like. As more information has been made available to the public concerning the hazards of indoor air pollution, there has been an increased demand for filtering devices that can be used to effectively improve air quality.
A self-contained, stand-alone air cleaning or filtration unit is normally employed to clean air in both residential and commercial settings. Stand-alone air cleaning units can assume a wide variety of forms, but generally include a housing maintaining one or more applicable filter materials and a fan or blower unit. The housing defines an inlet, at which the filter(s) is disposed, as well as an outlet or exhaust port. Most commercial applications include a false ceiling, such that the housing is readily "hidden" above the ceiling, with only the inlet (or an associated grille) being visible to persons within the room. During use, the fan or blower unit is operated to draw room air through the filter via the inlet. The filter material or media removes undesirable air-borne particles and/or gaseous contaminants/odors, such as dust, smoke, pollen, molds, volatile organic compounds (VOCs), etc. from the airflow. Following interaction with the filter material, the now "cleansed" air is forced, via the blower, back into the room through the outlet. A continuous intake and supply of air preferably generates a desired air re-circulation pattern within the room.
While the self-contained air filtration unit is well accepted, certain potential drawbacks have been identified. First, in an effort to optimize filtering performance, the stand-alone filtration unit is normally centrally located in (or over) the room of interest. Often times, one or more room occupants may work or otherwise be located in that same central area, directly below the air filtration unit. For example, a desk, chair, table, entertainment device, etc. may be positioned in the center of a room. For persons sitting, working or otherwise occupying this center area, the air-filtration unit may prove highly intrusive. Noise generated by blower motor operation can be distracting, making it difficult to concentrate, speak with others, etc. Similarly, forced air supplied from the air filtration unit's outlet may cause further room occupant discomfort. Second, for larger rooms, a single air cleaning unit may not provide adequate filter material surface area and/or two or more different areas of relatively heavy air pollution may exist within a single room. In either case, two or more air filtering units must be purchased and installed, thereby increasing overall costs. Simply stated, a single, self-contained air filtration unit cannot clean and re-circulate air in two, adjacent rooms. Even further, because the stand-alone unit does not have the ability to exhaust air outside the room, a negative pressure cannot be created, such that "fresh" air is not advantageously drawn into the room. An additional, albeit unrelated, concern arises during replacement of a filter. Because the filter is located directly adjacent the blower motor, the entire air filtration unit must be deactivated prior to filter replacement.
An alternative concept to the stand-alone filtration unit is a modular air-purification system. With this approach, a blower module and a filter module are separately provided and installed over a room of interest. Perhaps due to the wide acceptance of stand alone air filtration units, as well as the numerous engineering obstacles presented by a modular-configuration, only one modular-type air cleaning system has been identified, advertised as being available under the trade name Crystal-Aire.RTM. from United Air Specialties, Inc. of Cincinnati, Ohio. According to a trade brochure, this air-cleaning system includes separate blower and filter units designed to be connectable by a single duct. This configuration allows the blower unit to be installed apart from the filter unit. However, the blower unit has only one inlet port and one outlet port, such that the system is restricted to a single filter unit connected to the inlet port, and a single supply (or forced air return) unit connected to the outlet port. In theory, it may be possible to connect two or more filter units and/or supply units in series to the blower unit. Unfortunately, overall blower efficiency and recirculation may be greatly reduced.
Air-purifying systems are extremely popular and beneficial. However, the standard "self-contained" design is highly inflexible, and must be centrally located within a room of interest. As a result, the self-contained air-cleaning unit intrudes upon room occupants, leading to potential discomfort. Therefore, a need exists for a modular air-purifying system configured to optimize filtering and air re-circulation performance.